Many organisms need to shed their skin in order to grow or to get rid of parasites. Here are some interesting things that happened along the way.
When you have a strong appearance, there is only one way for you to continue to grow - to shed your skin.
"Arthropods" are the most prosperous group of animals on earth. Their entire bodies are covered in exoskeletons, which not only support their bodies but also protect them from predators. From a crab's shell to the shiny carapace of a ladybug, exoskeletons come in all shapes and sizes, but most are made of the same fibrous material - chitin.
When a young arthropod is ready to grow up, its hormones stimulate its skin to begin shedding, a process called molting. At this time, the outermost cuticle of the exoskeleton and the epidermal cells below it will begin to produce a new replacement cuticle; the arthropod will then inhale large amounts of air and squeeze the body fluids around the body to support the fragile sutures of the old skin. .
Oklahoma State University entomologist Andrine Shufran said, citing cockroaches as an example: "They will split in the center of their back and pop out within 20 minutes."
Aquatic crustaceans such as crabs , absorbing the surrounding water in order to exert pressure on the gaps in its body shell and squeeze itself out of the shell like letter paper in an envelope.
Christine Simon, an evolutionary biologist at the University of Connecticut , wrote in an email: "Because crustaceans shed an entire shell at a time, you can find crabs large and small on the beach. and horseshoe crabs scattered perfect little shells. "
As for arachnids such as hairy spiders and scorpions, they are less flexible. "So they popped the skull open and pulled everything out of the hole," Shufran said.
Follow the tail
Only in old-school comics do you see her emerging from a turtle shell; in the real world, Her shell is actually part of their skeleton. "[The turtle shell] is like a fine geometric design made up of a set of 50 bones," said Jeffrey E. Lovich, a survey geologist with the U.S. Geological Survey (USGS). 》
On the outer layer of the hard plate of the tortoise shell, scales composed of keratin are stacked. Lovich said she strips off the shields, which not only allows the shell to grow larger, but also helps get rid of the algae that clings to it.
Not all sea turtles shed their skin, said Whit Gibbons, an ecologist and professor emeritus at the University of Georgia who co-authored "The World's Sea Turtles: A Guide for Every Family" with Lovich. The time is also different.
For example, a painted turtle may shed its skin in a week, but a slippery turtle like the red-eared turtle may take a year.
When lizards are ready to shed their skin, their body color will usually darken, their eyes will appear cloudy, and they will begin to twist from side to side; they will rub their bodies against rocks or other rough surfaces, causing the old skin to crack. Lovich said the lizards will eventually find a way to escape, leaving behind what looks like nylon stockings of dead skin.
Although the discarded skin has no color, you can still identify the species of lizard or snake from the pattern on the skin, Giese said.
"It's like a black and white copy," Gies said. For example, the scarlet king snake has obvious red, yellow, and black stripes, corresponding to the various shades of gray when it sheds its skin; such as the size of the molt and the type of scales, can also be used as other clues to determine the snake species.
Molt can even point out the location of the previous owner. Just look at the tail, Gibbons says, "it's pointing in the direction the snake left."
Benefits Beyond Growth
Molting also helps animals get rid of external parasites that live inside their bodies. For example, when some Australian palace guards shed their skin, harmful mites will also fall off.
Some lizards and frogs eat their shed skin, called dermatophytes; cockroaches like the Madagascar eat their exoskeletons.
“It’s always good to hide any evidence of your existence."It's one of the ways to preserve the resources you put into survival," Shufran said. 》
After the animal sheds its skin, it may take half an hour or several hours for the animal's new skin to harden. Before that, they were vulnerable to injury or prey. The female Boston lobster will enter the male's cave to mate with the male after molting, and the male will guard the vulnerable female for several days.
